In a statement to an emergency meeting of the House of Commons, he said: "The policy of containment is not working. The WMD programme is not shut down. It is up and running."

Blair, speaking to MPs on Tuesday shortly after he released a dossier alleging that Iraq has "military plans" for chemical and biological weapons, said the past 11 years showed "a history of U.N. will flouted, lies told by Saddam ... obstruction, defiance, and denial."

"The case for ensuring Iraqi disarmament, as the U.N. has stipulated, is overwhelming," Blair said.

"I defy anyone on the basis of this evidence to say that is an unreasonable demand for the international community to make when, after all, it is only the same demand that we have made for 11 years and he has rejected."

Blair said military action and sanctions since 1998 had set the Iraqi programme back, but not ended it. (Key quotes)

In response, Iraq's General Amir Sadi, an advisor to Saddam Hussein, said: "The allegations are long, his evidence is short.

"His evidence is a hotchpotch of half truths, lies, short-sighted and naive allegations which will not hold after a brief investigation."

He said Iraq would give U.N. weapons inspectors "unfettered access" to suspected weapons sites, including those listed by Blair. (More reaction)

CNN's European Political Editor Robin Oakley said: "(Blair) was saying that one way or another inaction was not a possibility -- there has to be action of one kind or another."

"Mr Blair was questioned consistently about regime change and he kept on answering, 'no, our focus is on disarmament.'

"(Blair) said regime change would be nice but that was not a specific objective of the policy as far as he is concerned. And that creates a difference between him and (U.S. President) George Bush."

The long-awaited 50-page dossier on Iraq by the British security services says Saddam has retained authority over command and control arrangements to use chemical and biological weapons. (Main points)

The report concluded that Baghdad could deploy weapons of mass destruction within 45 minutes.

It also says he has tried to acquire "significant quantities" of uranium from Africa despite having no civil programme that could need it.

Iraq, it says, is five years away from producing a nuclear weapon on its own but this could be shortened to between one and two years if it managed to obtain weapons-grade material from abroad.

Saddam's "violent and aggressive" regime has tried to obtain technology and materials for use in nuclear weapons and has developed mobile laboratories for military use, it said.

Among its allegations, the dossier says Iraq has:

Continued to produce chemical and biological agents

Crawn up military plans for the use of chemical and biological weapons

Developed mobile laboratories for the production of biological warfare agents

Sought significant quantities of uranium from Africa

Recalled nuclear programme specialists

Illegally retained missiles with a range of 650km (400 miles)

The case for ensuring Iraqi disarmament, as the U.N. has stipulated, is overwhelming

-- UK Prime Minister Tony Blair

The document says Iraq has a programme for the development of missiles capable of reaching targets in Cyprus, Greece and Turkey, as well as all Iraq's neighbours in the Gulf region, including Israel.

It says Iraq has "tried covertly to acquire technology and materials which could be used in the production of nuclear weapons," and that "intelligence also shows that Iraq is preparing to conceal evidence of these weapons, including incriminating documents, from renewed inspections."

In a foreword to the report, Blair says: "I am in no doubt that the threat is serious and current, that (Saddam) has made progress on weapons of mass destruction and that he has to be stopped."

He said the document convinces him that Iraq must be dealt with.

His evidence is a hotchpotch of half truths, lies, short-sighted and naive allegations

-- Iraq's General Amir Sadi

He added: "Unless we face up to the threat, not only do we risk undermining the authority of the U.N., whose resolution he defies, but more importantly and in the longer term, we place at risk the lives and prosperity of our own people."